Scientists are analysing DNA in the dung of the Southern Cassowary to work out how many of the big weird endangered birds are left in Australia's tropical rainforests.

The researchers, based in the North Queensland town of Atherton, will shortly start their investigations at nearby Mission Beach. They hope to track the movements of the birds and the survival of their offspring, to help inform conservation efforts.

"Across cultures we think of cassowaries as being special, and in this area a lot of indigenous people consider them to be very special as well," says researcher Dr David Westcott from CSIRO Sustainable Ecosystems.

He says cassowaries are interesting from a scientific perspective because, like emus, they represent a very early development in modern birds.

He says most information about cassowaries is anecdotal. The most recent census was 20 years ago, estimated that there are between 1400 to 4000 cassowaries left in Australia's wet tropics.

Westcott and team hope to use DNA found in the cassowaries' dung as a proxy for the birds, to monitor their population.

He says the method is particularly good for species like cassowaries, which are very shy and occur in low densities.

Westcott says the method has been used before on bears, coyotes, northern hairy-nosed wombats and pandas, giving more reliable information for conservation.

"Tens of millions of dollars have been spent on panda conservation," says Westcott.

"But when they use this genetic technique, they realised they had twice the number of pandas in a particular set of reserves than they thought they had."

He says he doesn't know whether the cassowary census will come up with larger or smaller population estimates than we have to date.

DNA fingerprinting

Westcott's colleague, CSIRO molecular ecologist Dr Denise Hardesty, says seeds in the fruit that cassowaries eat scrape small amounts of DNA from the lining of the birds' intestines which ends up in their dung.

She says community volunteers will collect dung for the study and she will extract, amplify and analyse the DNA.

"Like with humans where you can do fingerprinting and identify individuals ... you can do the same thing with birds, plants and other organisms," says Hardesty.

The characteristic fingerprint of each animal is more similar the more related they are, which enables researchers to track offspring as well, she says.

Westcott says involving the community in collecting dung means he and Hardesty are able to do research that would otherwise be difficult to fund.

But, more importantly, he says the local community are "natural collaborators" in the work because cassowaries live on farms and in backyards.

"In those areas the local communities are really engaged in cassowary conservation and are really active in trying to understand their birds," he says.

So does cassowary dung smell? Not when it's fresh, says Hardesty.

"When you see the piles on the ground, you see entire fruits, you see seeds," she says. "It's a fresh fruit salad and it doesn't smell really bad if it is really fresh."

"When it's been sitting out there a while and it starts getting warm and mouldy then it doesn't smell super good - but it could be a lot worse."